title: Distortion of the terminal portion of the QRS is associated with poor collateral flow before and poor myocardial perfusion after percutaneous revascularization for myocardial infarction.
abstract: OBJECTIVE
  The distortion of the terminal portion of the QRS has been related to adverse outcome in patients with ST-segment elevation myocardial infarction.
  
  
  METHODS
  We studied the relationship of this electrocardiographic pattern with the angiographic findings in patients treated with percutaneous revascularization for ST-segment elevation myocardial infarction. We included 349 patients, 318 treated with primary angioplasty and 31 with rescue angioplasty after failed thrombolysis.
  
  
  RESULTS
  Eighty-five patients were found with distortion of the terminal portion of the QRS complex (group 1) and 264 without it (group 2). Collateral flow was absent in 30 patients (35%) from group 1, versus 52 patients (20%) from group 2 [odds ratio (OR) 1.806, 1.097-2.974, P 0.019]. No-reflow occurred in 12 (14%) patients in group 1 versus 17 (6.4%) in group 2 (OR 2.388, 1.091-5.230, P 0.016). Myocardial perfusion was graded 2-3 in 28 patients (58%) of group 1 versus 98 (76%) in group 2 (OR 0.443, 0.220-0.893, P 0.021).
  
  
  CONCLUSIONS
  Patients with ST-segment elevation myocardial infraction showing distortion of the terminal portion of the QRS have worse collateral flow, and present more often no-reflow or poor myocardial perfusion after percutaneous revascularization. These data contribute to explain the worse clinical outcome of these patients.
authors.affiliation: Cardiovascular Institute, San Carlos University Hospital, Marid, Spain. drchjcgr@arrakis.es
authors.forename: Juan C
authors.initials: JC
authors.lastname: Garcia-Rubira
authors.forename: Ivan
authors.initials: I
authors.lastname: Nuñez-Gil
authors.forename: Rafael
authors.initials: R
authors.lastname: Garcia-Borbolla
authors.forename: Maria C
authors.initials: MC
authors.lastname: Manzano
authors.forename: Antonio
authors.initials: A
authors.lastname: Fernandez-Ortiz
authors.forename: Migel A
authors.initials: MA
authors.lastname: Cobos
authors.forename: Leopoldo Pérez
authors.initials: LP
authors.lastname: de Isla
authors.forename: Rosana
authors.initials: R
authors.lastname: Hernández
authors.forename: Carlos
authors.initials: C
authors.lastname: Macaya
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D003097:Collateral Circulation / Q000502:physiology*; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000502:physiology*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome